However, they have ordered 12x A350s so that should be the first Airbus in ET fleet.
AIrbus has approached ET many times before and I expect them to continue to do so in the future. ET is not big but I would not think either OEM is going to ignore them, especially if their plan of being the largest carrier in Africa do pan out. And that doesn't even include their plans to create regional carriers throughout Africa, which should give the ET group a similar footprint as a LAN in Latin America, for instance.
The CEO's words, I am pretty sure, are not intended to put Boeing on notice. ET (and in fact Ethiopia) is FULL of Boeing fanboys and fangirls so his point should really be taken at face value. MAX has the advantage but NEO will be looked at, nothing more, nothing less. ET is very loyal to Boeing, and that is probably an understatement.
So how did they order the A350s? I don't have insider info but my guess is that:
1) they liked the specs AND
2) Airbus put forth an offer ET couldn't refuse
Not sure, perhaps Boeing did take ET for granted, I don't know. Certainly, ET like all other 787 customers was not happy with the many delays.
The argument went that ET is now big enough where it could justify planes from different vendors. This happened under the previous CEO; I think he was the only who could have made that happen as he was the architect of the new surge by ET starting in the early 2000s.